Patent GB-827616-A (GB)
Title: Improvements in or relating to presses
Inventor: SWINGLER AENEAS CHARLES JOHN
IPC: B30B9/10
Filed: 1956-08-31
Abstract: 827,616. Presses for separating liquids from solids. BRITISH WEDGE WIRE CO, Ltd. Aug. 29, 1957 [Aug. 31, 1956], No. 26755/56. Class 46. [Also in Groups VIII, XXIX and XXX] Conveyer band.-A conveyer band 201, Figs. 7A and B, of textile material (formed from, e.g., synthetic monofilaments or stainless steel wire) extends around the outside of a casing 202, the upper reach portion of the band being supported in a channel 202a, Fig. 8, and the lower portion passing over a roller 246 and under a roller 247, Fig. 7A. These rollers are mounted on a carriage 243 to which is pivoted at 245 a bell-crank member 244 secured to a double-acting ram 242, Fig. 7B, part of which moves in a cylinder 242a. The roller 246 is able to rotate in a clockwise direction only, while roller 247 is free. As the carriage is moved to the left by the ram the rollers rotate while the band remains stationary. Upon movement to the right the roller 246, being unable to rotate, exerts a pull on the band which is assisted by a pad 248 on the bell-crank member which is simultaneously brought into contact with the band. The band is thus moved. Platen and rams.-The main ram 213, Fig. 8, is hollow and open at the top and slides in a cylindrical bore in a head 211 supported by pillars 210 on the casing 202. A platen 203 faced with a solid rubber pad 204 is mounted so as to be slightly rockable on the end of the ram. The platen and main ram assembly may be rapidly lowered, until the pad 204 contacts the material to be pressed, by two double-acting rams 224, a valve 221 being open at this stage to permit free flow of hydraulic fluid between a tank 220 and the main ram and cylinder. Thereafter the valve 221 is closed and fluid supplied under high pressure via a bore 223 for the pressing phase. Subsequently the platen assembly may be rapidly retracted by the rams 224. An endless band 235 of the same material as the band 201 is carried by spring-loaded rollers 236 mounted on the platen, Figs. 7A and B, and has both its forward and return reaches passing under the platen. The outer reach on the righthand between two rollers 237, mounted in a fixed frame 238, which allow the band to pass freely during downward movement of the platen. During upward movement the rollers, moved upwards by friction with the band, are forced together by contacting two downwardlyinclined faces 239, whereupon the band is gripped at that place, and further upward movement of the platen causes movement of the band around its course on the platen. Drainage grid.-A drainage grid is provided in that part of the channel underlying the platen, and consists of bars 205, Fig. 8, whose ends curve around cross bars 206, Fig. 7B, the whole resting on cross members 207, Fig. 7B, integral with side members 208, Fig. 8. Gates.-To prevent soft material being forced outwards longitudinally of the band by the platen two gates 226, 227, raised and lowered in synchronism with the platen, are provided (shown one up, one down in Figs. 7A and B respectively). Gate 226 is mounted on a rod 230 slidable in a guideway 231 and has a further rod 302 engaging guideways 232 so that during movement by a ram 228 the lower edge 226a has a purely vertical motion. Gate 227 is identical. Operation.-Within the casing 202 there is provided a hydraulic circuit (see Group XXIX) for actuating the apparatus according to the following cycle. First, band 201 is advanced by ram 242. Then a timer is started, the platen assembly and gates 226, 227 are moved downwards by rams 224 and by rams 228, 229 respectively, a spreader (not shown) for the material is retracted and advanced, and ram 242 is retracted. When the platen encounters the material to be pressed, valve 221 is closed and high pressure fluid is applied to the ram through bore 223. When the timed stroke is completed the retraction of rams 224 is initiated, pressure through 223 ceases, and valve 221 is opened. At the upward limit of the stroke a limit switch operates to complete the cycle. A change-over switch permits the apparatus to perform one complete cycle only or repeated cycles. Alternatives and modifications.-The conveyer band 201 may, for its periodic advancement, pass around a crimped roller and a soft rubber roller, the latter being driven by a geared electric motor having a brake coupled to the abovementioned timer, Fig. 1, (not shown), as an alternative to the ram 242 and associated mechanism. In either case the step of movement may be equal to the width of the platen or to a fraction of it. Instead of the solid rubber pad 204 the platen 203 may be faced with a flexible bag which is filled with a fluid (preferably liquid) and which may bulge around the edges of the platen to form a peripheral seal. In Fig. 1 (not shown), the platen is a rectangular wooden block with a bevelled leading edge. In Fig. 4, (not shown) two presses are provided, spaced along the conveyer band above the casing ; one or both of the platens may be electrically heated, and one or both of the drainage grids is connected with a steam supply. The motor of the pump supplying the hydraulic circuit may be interlocked with an electric blower which cools the interior of casing 202.